Bad trip on Moon Lights

davidcalgary29

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My (unknown species, as it was mislabelled at LFS) fairy wrasse becomes extremely agitated whenever I activate the "moon light" setting on my Evo 13.5g; it even jumped out of the small at the top yesterday when I turned it on by accident. I noted this behaviour once before when I previously activated the "moon light" setting. The wrasse is fine today at the normal daylight setting. Has anyone experienced this type of reaction before? I'm stumped.
 
I've seen fish get stressed before when the light suddenly changes. It's an abnormal environment for the fish when everything is dark blue so it might just be getting stressed from that. It could be perceiving it as darker than usually when things suddenly get dark, you don't want to be there lol
 
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I've seen fish get stressed before when the light suddenly changes. It's an abnormal environment for the fish when everything is dark blue so it might just be getting stressed from that. It could be perceiving it as darker as usually when things suddenly get dark, you don't want to be there lol
Well, that does make some sense. I tried it again, and there was much splashing and agitation from that one fish. Lesson learned -- I'm keeping the moon lights off.
 
This is interesting. I wonder if the fish comes from an area that never gets moonlight filtered down to it in the wild. Maybe the spectrum bothers its eyes or impacts some other part of its body (other light sensory parts). It would be an interesting research paper if every fish of this species reacts the same way.
 
Having light suddenly turn on and off is not natural. The sun doesn't blink into noon and blink into night.

I try not to have any sudden lighting changes in my tank to minimize stress. Can you program your moon light to come on just before the main lights turn off? Also, do you have a ramp setting on your light so it can come on at a low intensity and slowly get brighter?
 
I think there is also a misunderstanding of the blue channel. Blue light is not moon light. The blue light on the fluval is likely a feature for those who want actinic lighting. Usually, moonlights are extremely dim and not really meant to illuminate the tank or be used in photosynthesis. The fluval blue channel is not that.
 
I think there is also a misunderstanding of the blue channel. Blue light is not moon light. The blue light on the fluval is likely a feature for those who want actinic lighting. Usually, moonlights are extremely dim and not really meant to illuminate the tank or be used in photosynthesis. The fluval blue channel is not that.
That's a fair point; I just used the terminology that most owners use for this particular setting -- although it's also worth noting that the PAR produced on this channel is below that of the normal "daytime" setting.

I'm going to have to look at switches to ramp up the lighting. It seems that Fluval no longer sells its product, and that's a shame.

I'm thinking that the fairy wrasse is particularly affected by this setting as it lives in the upper water column and is wild-caught. I just switched on the blues in my other Evo -- all stocked with captive-bred fish -- no visible reaction at all, and even from the radial filefish that lives at the surface.
 

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